Solid-liquid extraction is a process where compounds of a solid mixture, such as compounds in a matrix or bed of raw materials, are isolated by dissolving the desired compounds in an added solvent, where the extract is then further separated from the raw materials. As such, the process of solid-liquid extraction is often extensively utilized in a wide range of industries to extract desired bioactive and non-bioactive compounds for consumption. Examples of such compounds for consumption may be found in the following, but are not limited to, coffee beans, tea leaves, botanical herbs, spices, nutraceuticals, organic substances, and the like.
The control of the flow of incoming solvent entering the solid-liquid extraction apparatus and the flow of extracted effluent leaving the solid-liquid extraction is crucial for ensuring a properly performed and efficient extraction. This is because the flow of incoming solvent entering the solid-liquid extraction apparatus and flow of extracted effluent leaving the solid-liquid extraction are key factors in maintaining the continued compression and adjustment of hydraulic pressure exerted of the raw materials within the extraction apparatus. However, current technology pertaining to the solid-liquid extraction apparatus fails to further provide a device or a method that allows for the simultaneous control of the rate of solvent entering the extraction column and the extracted effluent leaving the extraction column, while also continuously maintaining the pressure within the extraction column.